Grate bar



p 1930- 7 J. T. TAWLKS 1,775,790

GRATE BAR Filed May 25, 1927 orJ ATTORNEY Patented Sept. 16, 1930UNITED; STATES PATENT OFFICE JOHN T. TAWLKS, or EVERETL'WASHINGTOUN,nssrenoit T TAw xs GRATE ms P NY, A CORPORATIONOEWASHINGTON I .1 'j-GRA'JJE BAR Application filed May 25,

This invention relates to improvements in grate bars for furnaces andthe like, and particularly to demountable, water cooled gratebars; itbeing the principal object of the invention to provide grate barscomprising disconnectible upper and lower sections that are cooled by acirculation of water through pipes that are disposed between the barsections but which are entirely separate therefrom so that the sectionsmay be easily and quickly demounted for'repair or replacement. 7

Other objects of the invention reside in the various details ofconstruction and combination of parts as is hereinafter described.

In accomplishing these objects of the invention, I have provided theimproved details of construction, the-preferred forms of which areillustrated in the accompanying drawings, wherein 1 a furnace grateformed by water cooled grate bars that are constructed in accordancewith this invention; the top section of the forward bar being removedfor better illustration.

Figure 2 is aplan view of the lower section of a grate bar as: assembledwith the water cooling pipe.

Figure 3 is a perspective view showing ends of the upper and lowersections ofa grate bar. V r g I n I Figure is a transverse section ofthe bar, taken on the line 414 in Figure 2.

Figure 5 is a partial plan view of an alternative construction.

Referring more in detail to the drawings- 1 and 2 designate oppositeside walls of a furnacefire box, by which a grate, designated-byreference numeral 3, is supported;

the grate consisting of a plurality of bars that are disposed closelytogether in parallel relation and'supported at their ends on shoulders 4formed by the walls.

or base, section 5 and an upper, or cap, section'6 and these,preferably, are of the same dimensions with respect to width and lengthand are fitted flatly together and held in assembled relation by meansof screws 7 extended therethrough. The upper sections are also providedat their ends with down- Figure 1 is a perspective view of a part of V19217. se aifio. 194,108.

wardly projecting lugs 8 adapted to seat within notches, or recesses,formed inthe ends 'ofthe lower sections'as a means of retaining theparts against displacement A The upper sections of the b arsmay beflat 5on top ormay have the top surfaces slightly crowned, as illustrated,and, extending'centrally of and in the longitudinal 'directionof thebars, are rows of apertures 9 and. likewise the adjoining edges of thebars are recessed 6 to provide openings '10 forthe passage ofair throughthe grate. I

Disposed between the ,upperand lower sections of 'eachbar is a'pipecoil112'forthe circulation of water as a cooling medium.

Thegcoil, asshown,:is of an elongated, U- shaped form extending nearlythe length of thebar, and is seated within similarly formed cooperatingchannels 13 and 14 in the adjacent faces of the bar sections in orderthat the (0; sections will not be held in spaced relation bythepipe. e g1 At one end of. the bar the .ends' of the pipe coil are turneddownwardly through recesses; 15 and 1 6 in the end of tllGrlOWBl barsection 1 5:, and are" connected, respectively, with cold water supplyand lead pipes 17 and E18; the connections with the latter 'pipesincluding cut-outvalves 19 and20. 1 c

In Figure 5 I have illustrated a construe 80,

tion in, which thewater ,p'ipes enter and leave the bar through notcheson its side edges instead of at the ends. This avoids weakening the endof the bar where strength is desired. I y

7 In the construction illustrated, it is readily apparent that thecooling coil of each bar receives a flow of cold water from the supplypipe and this passes through the coil to the drain pipe from which itmay be discharged, 9.0

or may be pumped into the boiler; the water beingslightly heated. Eachof the grate bars comprises a lower,

A bar cooled in the above manner will last many times longer than anuncooled bar; they will standup under greaterheat and 5 will requirepractically no cleaning, thus reducingthe expense of upkeep and the timeduring which boilers are kept out of commission for repair or cleaning.Such bars also give increased combustion as the air ducts do not becomeclogged with fused material.

It is to be noted also that each bar has an independent circulation ofwater and that the circulation may be cut 03 from any bar when it isdesired to disconnect and dismount the latter for replacement.Dismounting of the bars may be accomplished without the removal of thecoil or its disconnection from the circulating pipes.

It is evident that the bars may be made in any suitable form, in onepiece or cast in sections; that the coils may be varied in form andarrangement; that intake and outlet may be at the ends or anywherebetween, and Water introduced from the sides or from above or below thebars and accordingly I claim the right to vary the form and arrangementof the parts in accordance with the'principle of the invention.

Having thus described my invention, what I claim as new therein anddesire to secure by Letters-Patent, is:

A grate construction comprising in combination with water supply andreturn pipes, a plurality of base bars arranged in parallel edge to edgerelation, a plurality of cap or cover bars removably fitted to said basebars respectively and likewise arranged in edge to edge relation andtogether forming the top surface of the grate; each of said base barsand its cap bar being provided in their adjacent surfaces with groovestogether forming a channel that opens at its ends adjacent one end ofthe bar set, and a plurality of pipe loops, connected with the water supply and return pipes to afford circulation through said loops disposedwithin said channels between said base and cap bars but having no fixedconnection with any part thereof and permitting of disassembly andremoval of the bars without disturbing the loop or its connections.

Signed at Everett, Washington, this'18th day of May, 1927.

JOHN T. TAWLKS.

